A need is particularly felt of a method and an equipment that allow to monitor the conditions of a pregnant woman and her foetus before entering the childbirth room, and during the childbirth itself, in particular in childbirth stage 2 but even in stage 1 and 3. In particular, it is important to monitor such morphological and physiological parameters as uterine contractions intensity, frequency and duration, foetal cardiac frequency, endocervical canal dilation, endocervical canal length, foetal head station, in particular the distance of the foetal head from an anatomical reference, such as a parturient's bone, pubis, and the like, as well as the foetal head rotation, umbilical cord unwinding, and the evolution of all these parameters.
Various techniques are known for evaluating the imminence of the childbirth, and monitoring the childbirth progress. These methods provide the introduction of an operator's finger and/or such objects as sensors and/or instruments into the vagina, to reach the uterine cervix or the head of the foetus. These invasive techniques may also lead to infections and/or lesions of the parturient and/or the foetus.
Furthermore, in most cases the accuracy of the data that can be obtained depend upon the operator's sensitivity, therefore objectivity and precision of the measurement cannot be guaranteed. To cope with this problem, ultrasound devices have been developed such as the Barnev's cervicometer, described in Sharf et al., “Continuous monitoring cervical dilation and foetal head station during labor” (Med. Eng. Phys. 2007; 29:61-71). Barney's cervicometer comprises three ultrasound transmitters to be located on the abdomen of the pregnant woman, and a plurality of receivers to be located, typically, on the foetal head and at the edges of the cervical os. The analysis of the response time of the waves, and a subsequent triangulation of the distance obtained this way, allow to univocally evaluate the endocervical canal dilation and the foetus position. However, this device is still an invasive one, as well as the devices and the methods described in Shari et al., “Continuous monitoring cervical dilation and foetal reaction during labor” Medical Engineering & Physics 29 (2007) 61-71, in “Novel technologies for minimally invasive therapies”, Lupensis Biomedical Publications, as well as in WO199849942, WO2008084486 and WO2005015499. Apart from the nuisance they can cause to the pregnant woman, these techniques can only be employed if the pregnant woman keeps a lying-down position.
Furthermore, the operator must hold the ultrasound probe and continually adjust its position on the woman's abdomen.
Moreover, only a limited number of parameters can be displayed and monitored at the same time, normally no more than two, by means of known equipment.